Intramedullary nail

ABSTRACT

The present invention relates to an intramedullary nail. The said intramedullary nail comprises a hollow shank which is longitudinally slotted at its front end. The said intramedullary nail also comprises a mobilizable bar which passes through the said hollow shank. An expansion head is provided at the front end of the said mobilizable bar. A nut can be screwed onto the rear end of the said mobilizable bar.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an intramedullary nail, and moreparticularly to a device that can be passed directly through a brokenbone to secure the device at the position of the broken bone.

2. Description of the Related Art

Referring to FIG. 1 for the method of connecting a broken bone 1, a nail2 is passed through a medullary cavity. Since the nail 2 is in astraight and flat shape, therefore it is necessary to have an accessorynail 3 nailed into the radial direction of the surface of the medullarycavity to prevent the nail 2 from being fallen off from the medullarycavity when the nail 2 enters into the medullary cavity. In themeantime, it is necessary to use X-ray to complete the process ofprecisely pressing the plurality of accessory nails 3 on the nail 2 andconnecting a broken bone by a connecting means during a surgery in orderto precisely connect a broken bone. Such requirement not only increasesthe operation time, but also make it difficult for the newly grown bloodvessels and bone scars to effectively cover the bone and fuse the brokenbone. This shortcoming makes the application impractical and the patientpainful, and it is thus a major issue to medical people and patients.

To overcome the foregoing shortcoming, a crotched intramedullary nailwas introduced. Although the crotched intramedullary nail of this sorthas a crotched member disposed at the front end and pressing against themedullary cavity to directly fix the intramedullary nail into themedullary cavity when the crotched intramedullary nail enters into themedullary cavity, yet the crotched angle at the front end of theintramedullary nail is too small, and thus the intramedullary nailcannot press against the medullary cavity. If the crotched angle at thefront end of the intramedullary nail is too large, then theintramedullary nail cannot enter into the medullary cavity easily. Inthat case, a surgery tong is required to clamp the intramedullary nail.Since the surface of the intramedullary nail is very smooth, the tongcannot clamp the intramedullary nail easily and thus making theapplication very inconvenient.

SUMMARY OF THE INVENTION

Therefore, it is a primary objective of the present invention toovercoming the shortcomings of the prior art by providing anintramedullary nail that can be directly passed through a broken bone toconnect the broken bone.

The intramedullary nail comprises a hollow shank, a crotched memberextended axially and disposed at an end of the hollow shank, a pluralityof grooves extended axially between the crotched members, a mobilizablebar passed through the hollow shank, and an expansion head disposed atan end that passes through the hollow shank, such that the crotchedmember of the hollow shank can enter from an end of a broken bone andpassed through the broken position. A fixing means is pushed towards thehollow shank when the crotched member is pushed to the other end, sothat the mobilizable bar in the hollow shank will move towards thehollow shank as the fixing means moves, and the expansion headoriginally situated outside the crotched member is moved into the hollowshank accordingly. As a result, the plurality of crotched members ispressed by the expansion head and extended slowly to a predeterminedangle to fix the hollow shank and thus achieving the purpose ofconnecting a broken bone.

The mobilizable bar further comprises a fixing means disposed at an endaway from the crotched member, so that when the hollow shank is pushedinto the broken medullary cavity, the mobilizable bar in the hollowshank can be fixed into its position by the blocking of the fixingmeans, and thus preventing the plurality of crotched members from beingpressed by the expansion head or opening when the crotched member hasnot been pushed to a predetermined position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a prior art device;

FIG. 2 is a perspective view of the present invention;

FIG. 3 is a schematic view of the movements according to the presentinvention;

FIG. 4 is a schematic view of an intramedullary nail entering into themedullary cavity according to the present invention; and

FIG. 5 is a schematic view of fixing an intramedullary nail into themedullary cavity according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 2 for the intramedullary nail of the presentinvention, the intramedullary nail is a device capable of connecting abroken medullary cavity, and the device comprises a hollow shank 10,which is a hollow member in this preferred embodiment, and the hollowshank 10 includes more than one crotched member 11 extended axially fromthe periphery at an end of the hollow shank 10, and a groove 12 extendedaxially between the plurality of crotched members 11, so that thecrotched member 11 can be opened. The hollow shank 10 includes amobilizable bar 20 which is a rod passing through the hollow shank 10 inthis preferred embodiment, and the mobilizable bar 20 includes anexpansion head 21 disposed at an end where the mobilizable bar 20 passesthrough the crotched member 11, and the expansion head 21 is a conicalmember in this preferred embodiment that allows the expansion head 21 toenter into the hollow shank 10 easily. Further, the mobilizable bar 20includes a fixing means 30 exposed from another end of the hollow shank10, and the fixing means 30 is a nut in this preferred embodiment. Themobilizable bar 20 further includes a latching section 22 correspondingto the fixing means 30, and the latching section 22 is a thread in thispreferred embodiment.

Referring to FIGS. 3 to 5 for the use of the present invention, thecrotched member 11 of the hollow shank 10 enters into a medullary cavityfrom an end of the medullary cavity, and the mobilizable bar 20 of thehollow shank 10 can be fixed into its position by the blocking of thefixing means 30 when the hollow shank 10 is pushed into the brokenmedullary cavity, so that the expansion head 21 outside the crotchedmember 11 will not slide near to each crotched member 11, and thecrotched member 11 will not open when it is not pushed to apredetermined position. The hollow shank 10 is passed through the brokenposition from an end of the broken medullary cavity, and finally thefixing means 30 moves towards the hollow shank 10 when the hollow shank10 enters into another end of the broken medullary cavity, so that themobilizable bar 20 in the hollow shank 10 can move in the hollow shank10 according to the movement of the fixing means 30. The expansion head21 originally situated on the crotched member 11 moves into eachcrotched member 11 accordingly, so that the crotched members 11 arepressed by the expansion head 21 and slowly extended into apredetermined angle to fix the hollow shank 10 and achieve the purposeof connecting the broken medullary cavity.

1. An intramedullary nail, comprising: a hollow shank, having aplurality of crotched members disposed along the axial direction andextended from an end of said hollow shank; and a mobilizable bar,passing through said hollow shank and having an expansion head disposedat an end where said mobilizable bar passes through said crotchedmember, and said mobilizable bar being expanded from an end proximate tosaid crotched member to another end and said mobilizable bar having afixing means exposed from another end of said hollow shank.
 2. Theintramedullary nail of claim 1, wherein said expansion head isincreasingly expanded from an end proximate to said hollow shank toanother end.
 3. The intramedullary nail of claim 1, wherein said fixingmeans is a nut.